XVIII HOLOSTEI 499 
predaceous Fishes, with pointed teeth, rhombic scales, short dorsal 
and anal fins, a single jugular plate and prominent fulcra. The 
vertebral centra are represented by distinct hypo-and pleuro-centra, 
which may form complete alternating rings in the tail. 
The family first appears in the Trias and ranges throughout 
the Jurassic period. Hugnathus (Jurassic) and Lurycormus 
(Upper Jurassic). Caturus (Fig. 294) has a more extensive 
range, occurring in the Upper Trias of the Tyrol and in the 
Upper Jurassic of England and Bavaria. Catwrus and Eury- 
cormus, with their relatively thin, imbricated, cycloid scales, 
which have lost the peg-and-socket articulation, form connecting 
links between the more typical Huynathus and the Amiidae. 
Y, 
Md: 
Ly YI f iff, LAyiiiinnne 
Maieyeyy 2. 
OOOMGRMANG: 
Fic. 294.—Restoration of Caturus furcatus, omitting the squamation. x y. 
Upper Jurassic of Bavaria. (From Smith Woodward.) 
Fam. 5. Amiidae.—PBody fusiform and somewhat compressed. 
Seales uniformly thin, cycloid, and imbricated. Single dorsal fin 
long and low. Anal fin short. Tail nearly homocercal, with a 
rounded hinder margin. Fulcra absent from all the fins. 
Moderately large conical teeth are present on the premaxillae, 
maxillae, palatines and dentaries, and smaller teeth on the 
vomers, pterygoids, splenials and parasphenoid. Pre- and _post- 
centra fused in the trunk, forming complete bony amphicoelous 
centra, but distinct in the tail. A single large jugular plate is 
present. In the solitary living species the air-bladder is cellular, 
and its afferent arteries are derived from a posterior aortic arch. 
Pyloric caeca absent; Two peculiar comb-like structures are 
present on the throat. 
The Bow-Fin (Amia calva), the sole existing representative of 
the family, is abundant in the rivers and lakes of Central and 
Southern North America, including the great lakes Huron and 
